NICKEL BASE ALLOY PLASMA SPRAYED COATING FILM EXCELLENT IN WEAR RESISTANCE AND CORROSION RESISTANCE

摘要

PROBLEM TO BE SOLVED: To improve the wear resistance and corrosion resistance of sprayed coating film by specifying the compsn. of an Ni base alloy in a thermal spray material and dispersedly precipitating Ni-Cr-Mo-Ta intermetallic compounds into coating film after thermal spraying. ;SOLUTION: This sprayed coating film is composed of an aggregate of sprayed particles which are mutually fused via a surface oxidized layer formed in the process of passing through a thermal spraying atmosphere. The compsn. of sprayed particles used for the formation of the above coating is composed of the one contg., by weight, 15 to 30% Cr, 5 to 25% Mo and 1 to 9% Ta, and the balance Ni with inevitable impurities, and in the coating alloy matrix formed by thermal spraying, fine and hard Ni-Cr-Mo-Ta intermetallic compounds having a phase close-packed structure are dispersedly precipitated. Moreover, at the time of forming the coating film, it is preferable that the alloy powder in which the particle size is regulated to 10 to 100μm by gas atomizing and sieving is thermally sprayed in the air by a plasma gas compsn. in which the volume ratio of Ar/H₂ is regulated to 50/5.;COPYRIGHT: (C)1997,JPO